@awnlee jawkingIt wasn't (and isn't) uncommon for someone with issues of that sort to need extensive counseling. In the story, it's clear that, a month or two in, the character in question is still having strong suicidal thoughts and taking actions in support of them. Perhaps things would be very differetn in 2021; medicines have improved considerably (though can still have major issues).
Switching to the 'foreknowledge' statement, that's partly 1980 and partly simply 'reality'. You're slightly overstating things; he didn't expect that they could never be friends, rather that being lovers was over. He's always intended to remain friends. While they're physically isolated, they were in contact over the phone in a few weeks.
But, it being 1980, someone who attempted suicide wouldn't go back to the school they were in - at least, not someone whose parents could afford to put them somewhere else. The negative social pressures would be overwhelming. There's a perfectly obvious alternative in sight, that her parents can easily afford, and that would make her treatment team happy.
So, my main character forcing himself to decide things were over seems reasonable to me. Perhaps he could've decided to wait and see, but then he has his own flaws, which might be a factor in how he handled things.
Obviously, I could've written it to be 'faster', but that didn't feel realistic in this circumstance. Almost everything is left off the page, intentionally, because neither my main characters nor the reader should know the details. It's someone else's story. How much others reveal is how much they know, and besides someone letting them know that treatment is progressing, but hitting issues, and so forth, there's not much more to say.